Improvement in machines foe grinding the knives of mowing-machines



uiten tetes gas-trut ffies.

n.0.' GRONK, or AUBURN, NEW YORK, ASSXGNOR To HIMsE-LF AND W'. BoYNToN, or SAME PLACE.

Letters Patent No. 78,863, 'dated June `16, 1868.

IMPROVEMENT IN MACHINES POR GRINDING THB KNIVES 0I MOWING-MAGHINES.

TO ALL WHOM IT MAY CONCERN:

Be it knownthat I, M. C'. GRONK,.of -Auburn, in the county of Cayuga, and State of New York, have 'invented certain new and useful Improvements in Grindstone-Attachments; and I do hereby declare 'that the following isa full, clear, and hexact description thereof, reference beinghad to the accompanying drawings, and to the letters of reference marked thereonfwhich form a part of this specication, in which- Figure 1 is a plan view of-my reaper-knife grinder, and

Figure 2a side elevation of the same.

4 To enable others skilled in the art to make and use my invention, I will now describe its construction and operation.

A represents the frame off thegrindstone, constructedvin the ordinary way, withV the addition of the plati forms B B', which are`secured lto the under side of the outer ends of frame A. C designates a common grindstone. The platforms B B are each provided with a slot, s. lD represents a metal plate, resting on platform B', and made adjustable by means of a thumb-screw, passing through it and the slot s. To the face of D is firmly secured the plate e, in a vertical position, the object of which will be hereinafter set forth. E represents a a substantial metal plate, hinged at its lower end to. the ear-s t t 'on plate D. To the outer surface of E, and at right angles with it, is fastened the plate F, through which is the slot u, made in the segment of a circle.

It will he observed that the outer surface of plate F will rest against the inner surface of plate e, and that a thumb-screw, o, passing through e and the -slot in F, will regulate the position of the plate E, and thus-allow it to be placed nearer or further from the grindstone, as the case may require.

G designates a lever, witlra slot at its lower end, through which the thumb-screw m is made to pass. The inner end of the screw will work in a nut connected with plate E. On the screw m, and between the lever andthe nut, vthe spiral spring h is adjusted, for the purpose of throwing lever Goutward-when any pressure applied to it shall have been removed. l7e represents a bolt, passing through ears in the upper part of Gr, and

through similarears in the top pf plate E. The bolt answers as a fulcrum to lever G; and admitsfof said lever playing with a lateral motion, the object of which will be presently seen. lis a spiral spring,` placed on rod c, andgintended to keep lever G from changing its position unnecessarily.- H represents Athecutter-bar, to which theknves areattached. L is a similar bar, placed-immediately behind the cutting-bar H, and having two supports, a, attached to its under side, which act as restsV to the cutter-bar H. The two bars, H and L, are flush, andare kept in that position by the metal plate M. 'P designates-a dat-,headed bolt, 'the head of which rests on the plate M, and its body secured to the top of lever G. Through the head of P athumb-scrcw,j, isinsertcd, which passes through plate M, and serving as a pivot, upon which the said p l'atc and cutter-bar attached can be adjusted in reference to the grindstonc. The plate M is furnished with a rim on its under side and. front edge,

between `whichv rim and the bar L is the`cutter-bar I-I, which is allowed to slideso as to'plaoe the knives succcssivcly against the grindstone C.

It will be observedthat the bar L is secured Vto plate M by'the thumb-screws V V. W represents a rod,

' the inner-end of which is fastened to the top of lever G, and the outer end provided with a friction-roller, u.. VThe object of this roller is to counteract vthe bad eliects of inequalities on the side of the stone. This it does by moving the rod, which will' impart its motion to lever G, and to the cutter-bar and knives, in the manner already described. Y

In opera-ting my machine, the knife will be held in the proper posi-tion by pressing on the end of plate M, and the necessary pressure given to the knife by operating fever Gr with thumb-screw m. When there is a wabbling motion in the stone, theknife will partake of that motion bythe action of the pulley on lever G,

and the action of lever G on thc cutter-bar and knives.` 4By means' of this arrangement, the knife undergoing the process of grinding will always, when the stone wabbles, bear4 the same relative position to the surface of the stone, thus avoiding thc possibility of b lunting the edge of one knife while sharpening the one'next to it.-

Theapparatus for grinding can be transferred from one platform, B, to the other, when required.

What I claim as new, and desire to secure by Letters Patent, is

1. The Vcombination of the -plates D and E, arranged to operate as and for the purpose specified.

'2.` Lever G, rod k, and spring l, all combined and operating substantially inthe manner and forthe purpose set forth.

3, The combination of lever G, screw m, and spring h, arranged and operated substantially as and for the purpose speeifiedf 4. The combination of lever G, boit P, bars L and M, arranged and operating substantially for the purpose set forth. y

In` testimony that Lelaim the foregoing as my own, aiiix my signature in presence of two witnesses.

M. C` GRONK.

Witnesses:

HORACE T. Coon, JOHN BIRD. 

